As an isomeride of adriamycin, epirubicin pertains to an antibiotic antineoplastic drug, and has a mechanism of action of directly intercalating between a nuclear DNA base pair to interfere with a process of transcription and prevent an mRNA from forming, thereby inhibiting synthesis of DNA and RNA. In addition, epirubicin also has an inhibiting effect on Topoisomerase-II. As a cell cycle nonspecific agent, epirubicin is effective on multiple transplantation tumors and is widely used clinically.
Among known chemical synthesis methods for preparing epirubicin, a starting material is, for the most part, daunorubicin, for example, a method for preparing epirubicin by using daunorubicin developed by Farmitalia Corporation as a starting material (referring to U.S. Pat. No. 4,345,068 of Suarato et al). The core of the method is as below: oxidizing 4′-hydroxy of daunorubicin to ketone, conducting a stereospecific reduction along with loss of an optical center to obtain epi-daunorubicin by the required conformation, then brominating a segment of 14-CH3—C(O)— of epi-daunorubicin to obtain a segment of 14-CH2Br—C(O)—, and then obtaining HOCH2—C(O)-group by means of a hydrolysis reaction, thereby obtaining epirubicin. In the method for synthesizing epirubicin according to U.S. Pat. No. 5,874,550, it is also used the same starting material-daunorubicin.
Nevertheless, such synthesis processes need multi-step reactions to generate epi-daunorubicin, and then obtain epirubicin by means of bromination and hydrolysis reactions, which need numerous steps, have low yield (a mass yield is about 22-27%), and cause serious pollution by the bromination reaction and larger destruction of the environment. Therefore, it's necessary to further develop a method for preparing epirubicin in order to overcome the foregoing defects in the prior art.